By refactoring to deal with the !pud_huge(pud) || !pud_devmap(pud)
condition early it's possible to remove the 'ret' variable and remove a
level of indentation from half the function making the code easier to
read.
No functional change.
Signed-off-by: Steven Price <steven.pr...@arm.com>
---
Thanks to Jason's changes there were only two code paths left using
the out_unlock label so it seemed like a good opportunity to refactor.
---
mm/hmm.c | 69 ++++++++++++++++++++++++++------------------------------
1 file changed, 32 insertions(+), 37 deletions(-)
diff --git a/mm/hmm.c b/mm/hmm.c
index ca33d086bdc1..0117c86426d1 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -466,8 +466,10 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long
start, unsigned long end,
struct hmm_range *range = hmm_vma_walk->range;
unsigned long addr = start;
pud_t pud;
- int ret = 0;
spinlock_t *ptl = pud_trans_huge_lock(pudp, walk->vma);
+ unsigned long i, npages, pfn;
+ uint64_t *pfns, cpu_flags;
+ bool fault, write_fault;
if (!ptl)
return 0;
@@ -481,50 +483,43 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long
start, unsigned long end,
return hmm_vma_walk_hole(start, end, -1, walk);
}
- if (pud_huge(pud) && pud_devmap(pud)) {
- unsigned long i, npages, pfn;
- uint64_t *pfns, cpu_flags;
- bool fault, write_fault;
+ if (!pud_huge(pud) || !pud_devmap(pud)) {
+ /* Ask for the PUD to be split */
+ walk->action = ACTION_SUBTREE;
+ spin_unlock(ptl);
+ return 0;
+ }
- if (!pud_present(pud)) {
- spin_unlock(ptl);
- return hmm_vma_walk_hole(start, end, -1, walk);
- }
+ if (!pud_present(pud)) {
+ spin_unlock(ptl);
+ return hmm_vma_walk_hole(start, end, -1, walk);
+ }
- i = (addr - range->start) >> PAGE_SHIFT;
- npages = (end - addr) >> PAGE_SHIFT;
- pfns = &range->pfns[i];
+ i = (addr - range->start) >> PAGE_SHIFT;
+ npages = (end - addr) >> PAGE_SHIFT;
+ pfns = &range->pfns[i];
- cpu_flags = pud_to_hmm_pfn_flags(range, pud);
- hmm_range_need_fault(hmm_vma_walk, pfns, npages,
- cpu_flags, &fault, &write_fault);
- if (fault || write_fault) {
- spin_unlock(ptl);
- return hmm_vma_walk_hole_(addr, end, fault, write_fault,
- walk);
- }
+ cpu_flags = pud_to_hmm_pfn_flags(range, pud);
+ hmm_range_need_fault(hmm_vma_walk, pfns, npages,
+ cpu_flags, &fault, &write_fault);
+ if (fault || write_fault) {
+ spin_unlock(ptl);
+ return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk);
+ }
- pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
- for (i = 0; i < npages; ++i, ++pfn) {
- hmm_vma_walk->pgmap = get_dev_pagemap(pfn,
- hmm_vma_walk->pgmap);
- if (unlikely(!hmm_vma_walk->pgmap)) {
- ret = -EBUSY;
- goto out_unlock;
- }
- pfns[i] = hmm_device_entry_from_pfn(range, pfn) |
- cpu_flags;
+ pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
+ for (i = 0; i < npages; ++i, ++pfn) {
+ hmm_vma_walk->pgmap = get_dev_pagemap(pfn, hmm_vma_walk->pgmap);
+ if (unlikely(!hmm_vma_walk->pgmap)) {
+ spin_unlock(ptl);
+ return -EBUSY;
}
- hmm_vma_walk->last = end;
- goto out_unlock;
+ pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags;
}
+ hmm_vma_walk->last = end;
- /* Ask for the PUD to be split */
- walk->action = ACTION_SUBTREE;
-
-out_unlock:
spin_unlock(ptl);
- return ret;
+ return 0;
}
#else
#define hmm_vma_walk_pud NULL
--
2.20.1
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